Designing With Urbanite:Turning Construction Debris into

Beauty in the Garden

Text and Photos by Chris Drayer

It’s often said that one man’s junk is another’s

treasure. As a garden designer, I’ve always thought

that there is a corollary

to this: If you have

enough of any one

thing, it’s a resource.

The perfect illustration

of both of these ideas is

b r o k e n c o n c r e t e ,

referred to somewhat

facetiously as “Urbanite” or “urban stone” by savvy

gardeners. If you have ugly or cracked concrete

paving that needs to be replaced, all that material is

just going to cost you money to break up and haul

away to be ground up and recycled. However, if you

have significant grade changes in your garden,

consider the effect of a properly constructed dry-laid

broken concrete wall or pathway—especially if you

can’t afford either a stone veneer or an authentic stone

rubble wall but also can’t resign yourself to the rather

manufactured look of a keystone wall (or other

“landscape wall”

m a t e r i a l ) . A s

t h e s e p h o t o s

s h o w , t h e

irregular broken

edges, staggered

joints, and varied

thicknesses of

broken concrete

can create the natural look and permanence of a stone

wall or even suggest naturally exposed rock

outcroppings with all its varied colors. As a bonus,

you will create many new opportunities for planting,

both on top of the wall and between the courses.

There are a few tricks and techniques to keep in mind

to achieve a stable and natural-looking feature:

Choose appropriate material

Broken paving from either driveways or patios—as

opposed to foundation or wall rubble—makes the best SUMMER 2011 - PagE 11

Raw material

Walls and plantings with sloping grades

walls. This material usually comes in thicknesses of

between four and six inches, and the more uniform the

thickness, the easier it will be to work with. That said,

I refer you back to my corollary: I have successfully

incorporated curbings and foundations into my

constructions, especially to create steps. It’s very

important, though, to get pieces that are at least twelve

inches long in one direction, because a stable wall

needs to be at least that thick. It seems to be getting

harder to find good recyclable material because

contractors often load it directly into dumpsters.

Putting out the word to all your neighbors and friends

often pays off, or talk to contractors you see doing

demolition. They may agree (perhaps for a small

gratuity) to bring material to you, but you will want to

sort out as much unusable small rubble as possible

beforehand. I’ve also occasionally gotten material

advertised on Craigslist. It’s important to assemble

enough material to have a good selection before you

start, but ideally you also want to replenish your

stockpile during the course of the project because

there is an unavoidable tendency to use all the best

pieces first, leaving you with lots of problematic

chunks towards the end.

Compact the base and give the wall a batter

Depending on your soil and the steepness of the slope

you are working with, digging down into undisturbed

soil a few courses deep and compacting the soil with a

hand tamper will be fine for a wall of up to about four

feet high. You must ensure, however, that the wall has

sufficient batter—that is, a backward slant into the hill (next page)

Steps from salvaged saw-cut curb pieces will be faced with flagstone veneer

Designing with Urbanite (from previous page)

so that gravity helps support the structure; figure

about one to three inches of back slant per foot of

h e i g h t . U n l i k e a

monolithic masonry wall,

a dry-laid rubble wall

does not impede the flow

of water due to its many

gaps between pieces and

courses, and therefore it

does not need to resist the

hydrostatic pressure of

groundwater backing up

behind it. Over time there

may be some settling, but

because all the pieces can

move independently, the

wall will remain intact.

Overlap the pieces and stagger the joints

This is where artistry meets craftsmanship. It’s

important that each piece sits solidly on the one below

and that it fits reasonably closely to the one adjacent

so that no single

piece can slip

out of place. A

masonry chisel

and mallet are

you r f r i ends

here—use them

to knock off

errant knobs or

pebbles. This

process can still be quite time consuming, especially if

your material is irregular, so a way to cheat a bit is to

put some dirt, sand, or even mortar (which to me is

like admitting defeat) between layers to even things

out. I rarely use a level to check my work: instead, I

simply step back and just visually assess how it looks.

If one course contains some long pieces, I will take

the opportunity to use several smaller ones on the

Overlapping pieces of concrete

Step and wall construction

course above. You will always have more small pieces

than big, so look for ways to utilize them. Generally, I

save most of them for the last couple of top courses

and use the widest, longest pieces at the bottom.

Minimize the amount of retaining wall by sloping

the grade above and/or below

Unless you are growing rice, the planting areas above

or below a wall don’t need to be level—in fact, they

usually look better when they aren’t. I think of

topography like sculpture: the slope should have a

rhythm and flow that the plantings can then reinforce.

A flat place brings the eye to a stop, and while this

might be fine for a patio, it doesn’t make for appealing

plantings. To see this effect, take a look at photos of

the Grand Canyon:

notice how vertical

cliffs are separated

by sloping segments

of softer strata, and

see how sometimes

the cliffs disappear

in to the s lop ing

areas. Take a cue

from nature! In the

same vein—pardon

the pun—think about

the rhythm of the

walls themselves. Is

there anything more

boring than a series

of equally spaced, (next page)

Completed wall incorporating colored concrete pieces

Aloe saponaria planted during construction

SUMMER 2011 - PagE 12

Be silent. Be still.

Just watch everything come and go.

This is the way of Nature.

— Lao Tse

SUMMER 2011 - PagE 13

straight-line walls? Broken concrete lends itself to

gentle, undulating curves, so feel free to “sculpt” the

terrain by allowing the walls to subtly burrow in and

project out of an otherwise uniform slope.

A final thought

Like the act of creating all good stonework,

constructing a wall out of concrete rubble is a slow

and contemplative process—don’t plan on knocking it

out in a few days. You’ll ultimately be rewarded by a

work of art that gets more beautiful each year as your

garden plants embrace it. There go your weekends!

Chris Drayer, ASLA, is a landscape architect who has completed several projects in Mission Hills. He was the principal designer of the Rancho la Puerta gardens where he led a tour for MHGC members. Photos courtesy of and copyrighted by Chris Drayer.

Completed wall with sloping grade above

Designing with Urbanite (from previous page)

Nature does not complete things. She is chaotic. Man

must finish, and he does so by making a garden and

building a wall. — Robert Frost

Day Trip Delight:Sherman Library and Gardens

by Elaine Wilson

I’m always on the lookout for day trips that take me to

new places but get me home in time to feed my

German Shepherds. When a friend suggested the

Sherman Library and Gardens in Corona del Mar, it

was a perfect destination for us to explore. Opened to

the public in 1966, the Sherman Library and Gardens

began life in 1951 as the Sherman Foundation created

by Arnold D. Haskell, a man who dreamed of

developing a cultural center. Slowly, Haskell bought

up land until he owned a full city block measuring 2.2

acres, where the gardens

and research library are

located today.

After an easy ninety-

minute drive north, my

f r i e n d a n d I w e r e

greeted by delightful

blooms and sculptures;

upon further exploring,

we found many little

specialty gardens and

species plantings—a

s t a n d - o u t w a s t h e

towering camellia bursting with blooms against the

west wall. There was also a cactus and succulent area,

a large display shade garden, a rose garden, and a

tropical conservatory. On my next trip, I’ll visit the

non-circulating research library which has an

extensive collection of Pacific Southwest material.

Sherman Gardens reminds me of a mini-Huntington,

complete with a high tea offered the last Wednesday

of each month by reserva t ion only (ca l l

949-673-2261). There is a lovely garden restaurant

with innovative and tasty menu choices. Our last stop

was the boutique-style gift shop which is worth your

time to browse. After a full day of relaxing fun, we

were still back in San Diego by 3:30.

Elaine Wilson, a California native living in Mission Hills for 42 years, has chaired MGHC committees including Special Events, Hospitality, Fundraising, and Garden Walk Docents. Photo courtesy of and copyrighted by Jan Blakeslee.

Succulent garden Jan Blakeslee

SUMMER 2011 - pagE 24

Committee RESPONSIBILITIES

CommunicationsLinda Stanley

divinevine@aol.com

! E-News & Monthly Meeting Postcards

! Quarterly Newsletter

! Website

! Liaison to other community groups

EducationMary Shelley

rubyhart17@gmail.com

! Grants, Internships, Scholarships

! Reports & Record-keeping

! Encourage recipients to join in on club events

! Ask recipients to present a program at a meeting

HospitalityMartha Pehl

martha.pehl@sharp.com

! Meeting logistics

! Meeting refreshments

! Greet members

! Encourage members to participate in activities

MembershipLee Skillman

lee.skillman@ml.com

! Recruitment

! Record-keeping

! Greet members

! Membership renewals

Community ProjectsJeff Koch

jeffgkoch@mac.com

! Street Trees: plant trees in parkway areas

! Planter Boxes: Goldfinch & Washington Streets

! Petals for Patriots

! Hanging Baskets: Business District

! SD River Park: provide picnic tables & signage

! Concerts in the Park

! Pioneer Park: plant a large tree as focal point

Special EventsWally Hartwell

metreco@pacbell.net

! Coffee/Wine in the Garden

! Craft Events

! Field Trips

! Member Appreciation Party

Mhgc Mission StatementThe Mission Hills Garden Club was created to bring together friends and neighbors,

share our knowledge and love of gardening, and support and educate others in order to

make our community a more beautiful place to live.

Mission hills garden club Committee Structure